summaryrefslogtreecommitdiff
path: root/toxcore/net_crypto.h
blob: 56f43cc44a59f33d1a8754a340b2c1b235b7664f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/* net_crypto.h
 *
 * Functions for the core network crypto.
 *
 *  Copyright (C) 2013 Tox project All Rights Reserved.
 *
 *  This file is part of Tox.
 *
 *  Tox is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Tox is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Tox.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef NET_CRYPTO_H
#define NET_CRYPTO_H

#include "DHT.h"
#include "LAN_discovery.h"
#include "TCP_connection.h"
#include <pthread.h>

#define CRYPTO_CONN_NO_CONNECTION 0
#define CRYPTO_CONN_COOKIE_REQUESTING 1 //send cookie request packets
#define CRYPTO_CONN_HANDSHAKE_SENT 2 //send handshake packets
#define CRYPTO_CONN_NOT_CONFIRMED 3 //send handshake packets, we have received one from the other
#define CRYPTO_CONN_ESTABLISHED 4

/* Maximum size of receiving and sending packet buffers. */
#define CRYPTO_PACKET_BUFFER_SIZE 16384 /* Must be a power of 2 */

/* Minimum packet rate per second. */
#define CRYPTO_PACKET_MIN_RATE 8.0

/* Minimum packet queue max length. */
#define CRYPTO_MIN_QUEUE_LENGTH 64

/* Maximum total size of packets that net_crypto sends. */
#define MAX_CRYPTO_PACKET_SIZE 1400

#define CRYPTO_DATA_PACKET_MIN_SIZE (1 + sizeof(uint16_t) + (sizeof(uint32_t) + sizeof(uint32_t)) + crypto_box_MACBYTES)

/* Max size of data in packets */
#define MAX_CRYPTO_DATA_SIZE (MAX_CRYPTO_PACKET_SIZE - CRYPTO_DATA_PACKET_MIN_SIZE)

/* Interval in ms between sending cookie request/handshake packets. */
#define CRYPTO_SEND_PACKET_INTERVAL 1000

/* The maximum number of times we try to send the cookie request and handshake
   before giving up. */
#define MAX_NUM_SENDPACKET_TRIES 8

/* The timeout of no received UDP packets before the direct UDP connection is considered dead. */
#define UDP_DIRECT_TIMEOUT ((MAX_NUM_SENDPACKET_TRIES * CRYPTO_SEND_PACKET_INTERVAL) / 1000)

#define PACKET_ID_PADDING 0 /* Denotes padding */
#define PACKET_ID_REQUEST 1 /* Used to request unreceived packets */
#define PACKET_ID_KILL    2 /* Used to kill connection */

/* Packet ids 0 to CRYPTO_RESERVED_PACKETS - 1 are reserved for use by net_crypto. */
#define CRYPTO_RESERVED_PACKETS 16

#define MAX_TCP_CONNECTIONS 64
#define MAX_TCP_RELAYS_PEER 4

/* All packets starting with a byte in this range are considered lossy packets. */
#define PACKET_ID_LOSSY_RANGE_START 192
#define PACKET_ID_LOSSY_RANGE_SIZE 63

#define CRYPTO_MAX_PADDING 8 /* All packets will be padded a number of bytes based on this number. */

/* Base current transfer speed on last CONGESTION_QUEUE_ARRAY_SIZE number of points taken
   at the dT defined in net_crypto.c */
#define CONGESTION_QUEUE_ARRAY_SIZE 24

/* Connection ping in ms. TODO: calculate it per connection. */
#define DEFAULT_PING_CONNECTION 50

typedef struct {
    uint64_t sent_time;
    uint16_t length;
    uint8_t data[MAX_CRYPTO_DATA_SIZE];
} Packet_Data;

typedef struct {
    Packet_Data *buffer[CRYPTO_PACKET_BUFFER_SIZE];
    uint32_t  buffer_start;
    uint32_t  buffer_end; /* packet numbers in array: {buffer_start, buffer_end) */
} Packets_Array;

typedef struct {
    uint8_t public_key[crypto_box_PUBLICKEYBYTES]; /* The real public key of the peer. */
    uint8_t recv_nonce[crypto_box_NONCEBYTES]; /* Nonce of received packets. */
    uint8_t sent_nonce[crypto_box_NONCEBYTES]; /* Nonce of sent packets. */
    uint8_t sessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* Our public key for this session. */
    uint8_t sessionsecret_key[crypto_box_SECRETKEYBYTES]; /* Our private key for this session. */
    uint8_t peersessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* The public key of the peer. */
    uint8_t shared_key[crypto_box_BEFORENMBYTES]; /* The precomputed shared key from encrypt_precompute. */
    uint8_t status; /* 0 if no connection, 1 we are sending cookie request packets,
                     * 2 if we are sending handshake packets
                     * 3 if connection is not confirmed yet (we have received a handshake but no data packets yet),
                     * 4 if the connection is established.
                     */
    uint64_t cookie_request_number; /* number used in the cookie request packets for this connection */
    uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; /* The dht public key of the peer */

    uint8_t *temp_packet; /* Where the cookie request/handshake packet is stored while it is being sent. */
    uint16_t temp_packet_length;
    uint64_t temp_packet_sent_time; /* The time at which the last temp_packet was sent in ms. */
    uint32_t temp_packet_num_sent;

    IP_Port ip_port; /* The ip and port to contact this guy directly.*/
    uint64_t direct_lastrecv_time; /* The Time at which we last received a direct packet in ms. */

    Packets_Array send_array;
    Packets_Array recv_array;

    int (*connection_status_callback)(void *object, int id, uint8_t status);
    void *connection_status_callback_object;
    int connection_status_callback_id;

    int (*connection_data_callback)(void *object, int id, uint8_t *data, uint16_t length);
    void *connection_data_callback_object;
    int connection_data_callback_id;

    int (*connection_lossy_data_callback)(void *object, int id, const uint8_t *data, uint16_t length);
    void *connection_lossy_data_callback_object;
    int connection_lossy_data_callback_id;

    uint64_t last_request_packet_sent;

    uint32_t packet_counter;
    double packet_recv_rate;
    uint64_t packet_counter_set;

    double packet_send_rate;
    uint32_t packets_left;
    uint64_t last_packets_left_set;

    uint32_t last_sendqueue_size[CONGESTION_QUEUE_ARRAY_SIZE], last_sendqueue_counter;
    long signed int last_num_packets_sent[CONGESTION_QUEUE_ARRAY_SIZE];
    uint32_t packets_sent;
    uint64_t last_congestion_event;

    /* TCP_connection connection_number */
    unsigned int connection_number_tcp;

    uint8_t maximum_speed_reached;

    pthread_mutex_t mutex;

    void (*dht_pk_callback)(void *data, int32_t number, const uint8_t *dht_public_key);
    void *dht_pk_callback_object;
    uint32_t dht_pk_callback_number;
} Crypto_Connection;

typedef struct {
    IP_Port source;
    uint8_t public_key[crypto_box_PUBLICKEYBYTES]; /* The real public key of the peer. */
    uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES]; /* The dht public key of the peer. */
    uint8_t recv_nonce[crypto_box_NONCEBYTES]; /* Nonce of received packets. */
    uint8_t peersessionpublic_key[crypto_box_PUBLICKEYBYTES]; /* The public key of the peer. */
    uint8_t *cookie;
    uint8_t cookie_length;
} New_Connection;

typedef struct {
    DHT *dht;
    TCP_Connections *tcp_c;

    Crypto_Connection *crypto_connections;
    pthread_mutex_t tcp_mutex;

    pthread_mutex_t connections_mutex;
    unsigned int connection_use_counter;

    uint32_t crypto_connections_length; /* Length of connections array. */

    /* Our public and secret keys. */
    uint8_t self_public_key[crypto_box_PUBLICKEYBYTES];
    uint8_t self_secret_key[crypto_box_SECRETKEYBYTES];

    /* The secret key used for cookies */
    uint8_t secret_symmetric_key[crypto_box_KEYBYTES];

    int (*new_connection_callback)(void *object, New_Connection *n_c);
    void *new_connection_callback_object;

    /* The current optimal sleep time */
    uint32_t current_sleep_time;

    BS_LIST ip_port_list;
} Net_Crypto;


/* Set function to be called when someone requests a new connection to us.
 *
 * The set function should return -1 on failure and 0 on success.
 *
 * n_c is only valid for the duration of the function call.
 */
void new_connection_handler(Net_Crypto *c, int (*new_connection_callback)(void *object, New_Connection *n_c),
                            void *object);

/* Accept a crypto connection.
 *
 * return -1 on failure.
 * return connection id on success.
 */
int accept_crypto_connection(Net_Crypto *c, New_Connection *n_c);

/* Create a crypto connection.
 * If one to that real public key already exists, return it.
 *
 * return -1 on failure.
 * return connection id on success.
 */
int new_crypto_connection(Net_Crypto *c, const uint8_t *real_public_key, const uint8_t *dht_public_key);

/* Set the direct ip of the crypto connection.
 *
 * Connected is 0 if we are not sure we are connected to that person, 1 if we are sure.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int set_direct_ip_port(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port, _Bool connected);

/* Set function to be called when connection with crypt_connection_id goes connects/disconnects.
 *
 * The set function should return -1 on failure and 0 on success.
 * Note that if this function is set, the connection will clear itself on disconnect.
 * Object and id will be passed to this function untouched.
 * status is 1 if the connection is going online, 0 if it is going offline.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int connection_status_handler(const Net_Crypto *c, int crypt_connection_id,
                              int (*connection_status_callback)(void *object, int id, uint8_t status), void *object, int id);

/* Set function to be called when connection with crypt_connection_id receives a lossless data packet of length.
 *
 * The set function should return -1 on failure and 0 on success.
 * Object and id will be passed to this function untouched.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int connection_data_handler(const Net_Crypto *c, int crypt_connection_id, int (*connection_data_callback)(void *object,
                            int id, uint8_t *data, uint16_t length), void *object, int id);


/* Set function to be called when connection with crypt_connection_id receives a lossy data packet of length.
 *
 * The set function should return -1 on failure and 0 on success.
 * Object and id will be passed to this function untouched.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int connection_lossy_data_handler(Net_Crypto *c, int crypt_connection_id,
                                  int (*connection_lossy_data_callback)(void *object, int id, const uint8_t *data, uint16_t length), void *object,
                                  int id);

/* Set the function for this friend that will be callbacked with object and number if
 * the friend sends us a different dht public key than we have associated to him.
 *
 * If this function is called, the connection should be recreated with the new public key.
 *
 * object and number will be passed as argument to this function.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int nc_dht_pk_callback(Net_Crypto *c, int crypt_connection_id, void (*function)(void *data, int32_t number,
                       const uint8_t *dht_public_key), void *object, uint32_t number);

/* returns the number of packet slots left in the sendbuffer.
 * return 0 if failure.
 */
uint32_t crypto_num_free_sendqueue_slots(const Net_Crypto *c, int crypt_connection_id);

/* Return 1 if max speed was reached for this connection (no more data can be physically through the pipe).
 * Return 0 if it wasn't reached.
 */
_Bool max_speed_reached(Net_Crypto *c, int crypt_connection_id);

/* Sends a lossless cryptopacket.
 *
 * return -1 if data could not be put in packet queue.
 * return positive packet number if data was put into the queue.
 *
 * The first byte of data must be in the CRYPTO_RESERVED_PACKETS to PACKET_ID_LOSSY_RANGE_START range.
 *
 * congestion_control: should congestion control apply to this packet?
 */
int64_t write_cryptpacket(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length,
                          uint8_t congestion_control);

/* Check if packet_number was received by the other side.
 *
 * packet_number must be a valid packet number of a packet sent on this connection.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int cryptpacket_received(Net_Crypto *c, int crypt_connection_id, uint32_t packet_number);

/* return -1 on failure.
 * return 0 on success.
 *
 * Sends a lossy cryptopacket. (first byte must in the PACKET_ID_LOSSY_RANGE_*)
 */
int send_lossy_cryptpacket(Net_Crypto *c, int crypt_connection_id, const uint8_t *data, uint16_t length);

/* Add a tcp relay, associating it to a crypt_connection_id.
 *
 * return 0 if it was added.
 * return -1 if it wasn't.
 */
int add_tcp_relay_peer(Net_Crypto *c, int crypt_connection_id, IP_Port ip_port, const uint8_t *public_key);

/* Add a tcp relay to the array.
 *
 * return 0 if it was added.
 * return -1 if it wasn't.
 */
int add_tcp_relay(Net_Crypto *c, IP_Port ip_port, const uint8_t *public_key);

/* Return a random TCP connection number for use in send_tcp_onion_request.
 *
 * return TCP connection number on success.
 * return -1 on failure.
 */
int get_random_tcp_con_number(Net_Crypto *c);

/* Send an onion packet via the TCP relay corresponding to TCP_conn_number.
 *
 * return 0 on success.
 * return -1 on failure.
 */
int send_tcp_onion_request(Net_Crypto *c, unsigned int TCP_conn_number, const uint8_t *data, uint16_t length);

/* Copy a maximum of num TCP relays we are connected to to tcp_relays.
 * NOTE that the family of the copied ip ports will be set to TCP_INET or TCP_INET6.
 *
 * return number of relays copied to tcp_relays on success.
 * return 0 on failure.
 */
unsigned int copy_connected_tcp_relays(Net_Crypto *c, Node_format *tcp_relays, uint16_t num);

/* Kill a crypto connection.
 *
 * return -1 on failure.
 * return 0 on success.
 */
int crypto_kill(Net_Crypto *c, int crypt_connection_id);

/* return one of CRYPTO_CONN_* values indicating the state of the connection.
 *
 * sets direct_connected to 1 if connection connects directly to other, 0 if it isn't.
 * sets online_tcp_relays to the number of connected tcp relays this connection has.
 */
unsigned int crypto_connection_status(const Net_Crypto *c, int crypt_connection_id, _Bool *direct_connected,
                                      unsigned int *online_tcp_relays);

/* Generate our public and private keys.
 *  Only call this function the first time the program starts.
 */
void new_keys(Net_Crypto *c);

/* Save the public and private keys to the keys array.
 *  Length must be crypto_box_PUBLICKEYBYTES + crypto_box_SECRETKEYBYTES.
 */
void save_keys(const Net_Crypto *c, uint8_t *keys);

/* Load the secret key.
 * Length must be crypto_box_SECRETKEYBYTES.
 */
void load_secret_key(Net_Crypto *c, const uint8_t *sk);

/* Create new instance of Net_Crypto.
 *  Sets all the global connection variables to their default values.
 */
Net_Crypto *new_net_crypto(DHT *dht, TCP_Proxy_Info *proxy_info);

/* return the optimal interval in ms for running do_net_crypto.
 */
uint32_t crypto_run_interval(const Net_Crypto *c);

/* Main loop. */
void do_net_crypto(Net_Crypto *c);

void kill_net_crypto(Net_Crypto *c);



#endif